how to use bond_style fene/expand

a) please always reply to the list.
b) your input specifies bond_style fene and not fene/expand

axel.

it doesn’t matter, no matter fene or fene/expand, it doesn’t work. I am so new to Lammps, so I don’t even know how to check for the problems whenever there is error.
I tried to separate a few commands to see how it goes, but sometimes, it says: ERROR: Invalid value in set command (set.cpp:282)
,sometimes, ERROR: Incorrect args for bond coefficients (bond_fene.cpp:154)

it doesn't matter, no matter fene or fene/expand, it doesn't work. I am so
new to Lammps, so I don't even know how to check for the problems whenever
there is error.

a) there has to be somebody near you that has experience in lammps.
    it will be better to ask that person at the beginning.
b) don't try *your* project first, but rather try understanding
    some of the simpler ones in the examples folder.
c) build your input step-by-step and solve each problem one at a time.

with the current approach you are making your life needlessly
difficult and are wasting your own time and that of others.

I tried to separate a few commands to see how it goes, but sometimes, it
says: ERROR: Invalid value in set command (set.cpp:282)
,sometimes, ERROR: Incorrect args for bond coefficients (bond_fene.cpp:154)

those error messages are for a reason.
you have to *understand* that reason
rather than just silence them.

please use some common sense.

axel.

I would add that when LAMMPS says a particular
input script command is illegal or invalid, then
the best thing to do is carefully read
the doc page for that command and compare
it to what is in your input script. You should
always find a mis-match.

Steve